


Erroneous Zones

by Adenil



Category: Star Trek: The Original Series
Genre: Anal Fingering, Bones is just trying to be a good doctor, M/M, Non-Human Genitalia, Oral Sex, Rimming, Touching, Vulcan anatomy, what if Vulcans were made for sex?
Language: English
Status: Completed
Published: 2017-07-15
Updated: 2017-07-15
Packaged: 2018-12-02 06:47:46
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 7,147
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/11503959
Author URL: https://archiveofourown.org/users/Adenil/pseuds/Adenil
Summary: In order to ensure he doesn't offend Spock, McCoy needs to know where his erogenous zones are. But when Spock doesn't have a clue where they are the two of them employ a more...hands-on approach to finding out.





	Erroneous Zones

**Author's Note:**

> [tumblr prompt](http://adenil-umano.tumblr.com/post/162997508680/mccoy-asking-spock-if-vulcans-have-different%22): McCoy asking Spock if vulcans have different erogenous zones and Spock's not too sure what the norm is for either species or how his may differ. McCoy points out his own and encourages Spock to explore in his own time. Spock comes back saying he had trouble discerning anything, which leads to some very active cooperation from McCoy.

It took McCoy three months to finally convince the Vulcan High Command to send him something—anything!—on the biological makeup of Vulcans. Spock had already wound up on his operating table twice during that time. Thankfully both had been minor incidents and his xenobiology training had carried him through, but he still hated not knowing what made Spock tick. When he’d agreed to work on the _Enterprise_ he thought his xeno training would be for new species, not that he’d have to be making guesses about species that were already _in_ the Federation.

When the files appeared on his computer he breathed a sigh of relief. He blocked off the rest of the afternoon to look through them. Some of it he had already figured out: things like organ placement, bone structure, blood makeup, resting vitals. A few things were new, like this frankly-mystical sounding nonsense about a “healing trance.” Despite his request for the council to send him _everything_ the file was still redacted majorly. In particular the section on reproduction was sorely lacking. There were only two pages of information and one of them was a picture of a Vulcan-shaped silhouette. The silhouette was highlighted green for zones which could be touched and red for zones which could not. The entire thing was red.

Well, that was unhelpful. What if Spock needed a well-Vulcan exam? Was he supposed to just fly back to his home planet once a year? And how could he knew what was okay for a Doctor to touch if the whole damn body was off-limits?

He’d been putting off having a conversation with Spock about this until after he read the files from the High Command. He and Spock tended to butt heads more often than not and he didn’t want to start a ruckus by asking too many questions. He preferred to save any ruckus for special occasions. But this had gone on long enough. He needed to know about Vulcan anatomy and so Spock was just going to have to tell him.

He pressed the intercom. “McCoy to bridge.”

“Bridge, Uhura here.”

“Is Spock around? I need to see him.”

“He’s running data analysis at his station.” There was the muffled sound of talking, and then Uhura again, “He says he’ll be with you shortly, Doctor.”

“Thank you, Lieutenant. McCoy out.”

He cut the comm and sat back to mentally catalogue the questions he had. He had about a million of them, and was still thinking when Chapel paged him to say Spock had arrived.

McCoy grabbed his datapadd and went out. “Mr. Spock. Just the Vulcan I wanted to see.”

Spock raised his brow at him. McCoy still hadn’t figured out if that was a look of general confusion or if Spock found him distasteful. “As you requested my presence you should not be surprised to see me.”

“Still a stellar conversationalist, I see. Let’s go to the examination room.”

The examination room was cordoned off from the rest of the Sickbay and McCoy hit the indicator to put it in quiet mode. The walls would be soundproofed in case anything sensitive came up and Chapel would know not to disturb them. There was an exam bed beneath the mounted wall scanner, a chair, and a table filled with any supplies he could need.

Spock followed after him like an eerie shadow. “Do you have a concern for my health, Doctor?”

“No. In fact that’s what I’m hoping to prevent.” He patted the bed and Spock looked at him drily. He rolled his eyes. “Get up here and I’ll explain.” He waited until Spock obeyed and was sitting primly on the edge of the bed. “I’ve just received a communique from the Vulcan High Command. They finally sent me what they think I need to know about treating Vulcans. Unfortunately, what they think I need to know and what I _actually_ need to know are worlds apart.”

Spock’s eyebrow went up again. “I would have expected them to deliver all relevant files to you at the beginning of my posting here.”

“Well, they didn’t. It took a mountain of paperwork just to get them to send me as much as they did. I’m hoping you can help me fill in the blanks?”

Spock nodded. “It is logical for you to be equipped with the tools necessary to ensure my health.”

Well, this was off to a good start. McCoy couldn’t remember the last time he and Spock had been on the same side in an argument. “Agreed. Let’s start where they’ve sent me the least information. What can you tell me about Vulcan reproduction?”

Spock clammed up like an Aldebaran shellmouth.

“...Anything?”

“It is...not often discussed with outworlders.”

McCoy looked to the ceiling for deliverance. “Spock, I’m your doctor. Nothing you tell me is going to leave this room. Here, let’s start with something basic. Humans around our age usually get regular exams to detect cancers and the like. Do Vulcans do the same?”

Spock shifted uncomfortably, and there was a sight to behold. Spock uncomfortable. McCoy had never seen him like this. “In terms of a typical Vulcan lifespan I am not yet quite as old as you.”

“Quit deflecting.”

His lips pursed. “Not to my knowledge. However...once every seven years we are to return home to Vulcan.”

“That long? I suppose that makes sense, given your greater life expectancy. Alright, what about this?” He showed Spock the red figure of do-not-touch zones. “For humans our taboos against touch at the doctor’s office are, let’s just say _far less strict_. We mostly just avoid stimulating erogenous zones.”

Spock frowned. “Erogenous zones?”

“Yes.” When Spock continued to look confused McCoy shifted uneasily. “I mean, you know… Surely you know what I’m talking about?”

“I infer you imply an area of the body sensitive to sexual stimulation, but why ‘zones?’”

McCoy tried not to gape. Maybe teenage Vulcans didn’t play doctor in dark rooms—given their apparent taboo regarding anything sexual that made sense—but had Spock really never touched himself? “Certain areas are more sensitive than others on humans, but species differ. If you could tell me what might bother you I’ll be sure to avoid the area or at least take precautions during exams.”

“I see. I admit that I do not know the norm for either of our species, and so I cannot tell you where my body differs from yours.”

“Well,” McCoy said, looking down at his padd. He hadn’t expected to give the birds and the bees talk today, but what the hell? May as well. “The genitals are the main area in humans, although that’s not true across all species. Axanar find stimulation of the genitals to negatively affect sexual desire, for example. The specific area matters as well, but pretty much anything around the penis, labia, testicles, vagina, or clitoris would be a safe bet. Of course, it depends on the sex of the human in question.” He glanced up.

Spock was watching him intently. “Of course,” he agreed.

McCoy looked back at his padd and didn’t blush. Really. “The mouth is a highly sensitive area. Nipples are a hotspot, although depending on the mix of hormones in the body they’ll be more or less sensitive. Also the neck and—” _Don’t look, don’t look, don’t look_ —“the ears.”

Spock made a considering sound. “I see. I was not aware.”

McCoy felt like screaming. “Well,” he said with forced cheerfulness. “It’s really something you should discover for yourself. Maybe you can get back to me on that one. Let’s tackle the rest of the file…”

He grilled Spock for another hour about all the holes in the file. Spock told him what he could, which was quite a lot, considering Spock wasn’t trained as a doctor. That analytical mind had apparently absorbed every piece of information he’d ever been exposed to about the Vulcan body. Finally they were done and Spock slipped from the biobed and gave McCoy a curt nod as he departed.

Afterwards McCoy went and wrote up his notes. He filed them under “classified” in deference to Vulcans’ concerns about knowledge like this getting out and fully expected the issue to never come up again.

A week later, however, Spock was again standing in the Sickbay with his arms folded behind his back and a sour look on his face.

“What can I do you for, Mr. Spock?”

“I require a consult, Doctor,” Spock said, walking with purpose towards the examination room.

Surprised and worried, McCoy hastened after him. He made sure to put the room on quiet mode so they wouldn’t be disturbed. “Something the matter?”

Spock spun on his heel and glared at McCoy. “It did not work.”

“Work?”

“I attempted to follow your direction and locate my erogenous zones. It did not work.”

McCoy flushed hot as the image of Spock nude and _masturbating_ came unbidden into his mind. He blinked rapidly to dispel the thought but the mental image remained burned into his mind. “Oh?” he managed after a moment.

Spock squinted at him. “I believe I require more direction.”

McCoy raised his hand to his mouth thoughtfully, but also to prevent himself from bursting into giggles. “Spock, I’m not sure what I can do for you.”

“Your instructions lead me to believe you require this information. I would not have attempted to gather it otherwise.”

Really? Spock didn’t…? McCoy shook off the thought. _Not the time_. “That information would be helpful, yes. How did you, uh...what was your method?”

“I removed my clothing and adjusted the temperature of my quarters to 45 degrees.” Spock frowned as McCoy whistled under his breath. “I applied my hands to my body starting from the neck down, but was ultimately unsuccessful in locating any ‘zones’ which increased my desire for sex. I repeated the procedure each night over the course of five days, but the results did not vary.”

McCoy gaped at him, eyes hazy as he pictured Spock running those long fingers down his chest, over the slope of his stomach towards—He shook himself again. “What was the problem?”

“Each area felt much the same as any other.”

He hummed thoughtfully. He took a good look at Spock and tried to judge his mood. Spock was standing very straight and still wearing that small glare. His hands were folded behind his back. McCoy often saw him standing like that when he was frustrated with something but didn’t want to admit it.

“Could it be that it’s in a spot you can’t reach? Your back maybe?”

Spock looked thoughtful at that, and his shoulders relaxed as he went into problem-solving mode. “I had not considered that possibility.”

“Are you sure you tried everywhere? Maybe you missed a spot.”

“I did begin with the areas you indicated humans find pleasurable.” Spock considered for a moment and then said, “Doctor, you possess a scientifically-inclined mind.”

“Er, well I like to think so.” McCoy was surprised Spock would say something like that. Just yesterday Spock had called him irrational and accused him of using beads and rattles to practice medicine. But then, maybe Spock had been suffering a case of Vulcan blue balls. If so McCoy could forgive him for being snappish. “I didn’t study medicine for ten years without picking up a few things.”

“Then perhaps you would be willing to assist me?”

“Assist…” His words died in his throat as he realized what Spock was asking him to do. Spock wanted him to—to touch him. To put his hands on Spock’s body in search of what made Spock squirm with pleasure. McCoy tried to think of a tactful way to get the hell out of the situation before he embarrassed himself, but the look on Spock’s face gave him pause.

Spock’s brown eyes were hooded, his gaze slightly introspective but also contemplative. This was just science to Spock. Embarrassing science. And Spock was trusting him to be a professional.

McCoy stood a little straighter. “Of course, Spock.”

Spock seemed to relax further at his words. “I will defer to your medical expertise regarding how we should proceed.”

Okay. McCoy took a deep breath and thought, _okay_ , again. That was a lot of pressure. “Let’s, uh, try your back? Take off your shirts.”

Spock nodded and gripped the hem of his outer uniform top. He yanked it up over his head and began folding it neatly. Up until that moment McCoy hadn’t expected him to really do it, but Spock merely set the shirt aside and then performed the same maneuver on his thermal undershirt. Spock undressed in a rather demure way, McCoy thought. When McCoy took off his shirt he would usually tug at his collar and pull it off in one fell swoop. But the way Spock undressed meant his undershirt didn’t ride up unexpectedly.

Not that it mattered now, since Spock was topless. McCoy had seen him like this before but it had always been under dire circumstances and usually with a lot more blood. As Spock folded his shirts and set them on the table McCoy studied his pale shoulders and narrow waist, the dimples of his spine at his lower back, the gentle slope of his neck. When Spock turned McCoy couldn’t help but notice the slight green flush on Spock’s hirsute chest, his olive nipples, the soft-looking skin of his stomach. He tried to note these things with the dispassion of a scientific mind, but truly seeing Spock half-nude and standing again at parade rest did funny things to his insides. He decided it was just the surprise of seeing Spock like this.

“Do you—” He gulped. “Do you need me to turn the heat up?”

“The temperature is not yet uncomfortable.”

“Alright, then, come here.” He waved Spock over and had him face the biobed. He applied the disinfectant field to his hands as he spoke. “Standing first, I think. I’ll just try out your back and you let me know if there’s any reaction.”

Spock nodded curtly and stood with his arms loosely at his sides, his legs slightly apart.

“Okay, first touch.” He rested the palm of his hand between Spock’s shoulders.

Spock jumped at the contact.

“Sorry, my hands are cold,” McCoy muttered. He took his hand away and rubbed his palms together briskly before reapplying.

Spock softened under him. McCoy started to move around, brushing lightly over Spock’s skin. He traced over each centimeter carefully, methodically, doing his best not to miss any of Spock soft back. Spock’s skin was warm to the touch and smoother than he would have expected. He thought of flower petals.

Spock bowed his head as McCoy trailed his fingers up his neck, stopping at the short hairs at the base of his skull, and then back down, all along his spine until he could thumb the indents just above his bottom that had so interested him before.

“Anything?”

“Yes,” Spock said simply.

McCoy chuckled. “Can you be a bit more specific? This is for science, after all.”

Spock considered as McCoy continued to touch him, retracing the path until he was just lightly resting his hand between Spock’s shoulder blades. “The feeling is the same regardless of where you touch me.”

McCoy hummed. He realized he was brushing a circle with his thumb and he dropped his hand and took a step back. Spock’s uniform slacks had fallen low on his waist and McCoy could see just a hint of the curve of his bottom peeking above them. “That doesn’t make sense. I’ve seen how Vulcan nerves are clustered and they aren’t uniformly distributed.” But then again, Spock was only  _half_ Vulcan. Could it be his nerves were some odd mix?

Spock turned around to meet his gaze, apparently unconcerned that he was still shirtless. “The sensation was slightly different from when I touched myself.”

Fuck, those words. McCoy blinked to clear the image of Spock writhing beneath his own hands from his mind. “You think that means we’ve found it?”

“It may simply indicate that there is a mild telepathic effect which changes the...tenor of my reaction. In order to be certain you must also touch an area which I have already assessed, so that we may compare the reaction.”

That seemed reasonable. Or maybe McCoy was just starting to lose it from looking at Spock’s nipples, pebbled in the cold ship air. They stared back at him, accusatory. “You said you started at your shoulders?”

Spock nodded. His gaze dropped as McCoy stepped towards him and rested his fingers on the end of Spock’s collar bone. This was fine, McCoy told himself as he pressed a little harder, just enough to see Spock’s skin dent with the force of his fingers. He could feel Spock’s muscles tensing and relaxing, the steady pulse of his heart. He trailed down to the upper edge of Spock’s pectoral and flickered his gaze up to watch Spock’s face. He hadn’t been able to see his reactions earlier, but now he couldn’t look away. Spock’s gaze was unfocused, as though he were calculating a particularly complex equation. He stared at a spot just above McCoy’s shoulder with his lips slightly parted. They looked so pink that for a split second McCoy wondered if Spock wore lipstick.

“How is this?” McCoy asked.

“The sensation is no—” He stopped abruptly as McCoy’s index finger brushed against his right nipple.

McCoy raised his eyebrow, not really surprised but willing to fake it. “This is a good spot?”

“I am uncertain—perhaps the cold—” Spock shifted under his touch, his chest yearning forward as McCoy shifted so that he could brush his thumbs over Spock’s peaked nipples.

McCoy pressed the pad of his thumb down, hard, and then released the pressure. He pushed both nipples up and then rolled them hard as Spock’s gaze grew even more unfocused. “I certainly think we’ve found one of your erogenous zones.”

Spock nodded thoughtfully, raising both brows in his usual look of _fascinating_. “Indeed.”

He should have dropped his hand. There was no reason to keep touching Spock there, except that it stopped him from doing what he really wanted to do which was bend his head to take Spock into his mouth, bite at him, tongue him until Spock’s careful Vulcan stoicism crumbled between his lips. Instead McCoy brought together the thumb and forefinger of one hand and pinched as the other thumb flicked up and down rhythmically. “Which is better?” he asked, manic.

“Both are...intriguing,” Spock said. At some point he must have licked his lips. They were glistening. “It is curious.”

“What is?”

“The sensation is more intense here, but it is no different from my reaction when you touched other areas of my body.”

Fuck. Goddamnit. Spock wasn’t immune to pleasure, he really just felt it _everywhere_. He was just one giant erogenous zone perfectly tuned for sex. McCoy imagined Spock laying in bed, getting turned on no matter where he touched himself and being _disappointed_ by that result. He stilled his hands and counted to ten before physically forcing himself to step back.

He dropped his arms to his side, feeling stupid. “It sounds like your erogenous zones are more diffuse than a human’s,” he said, voice scratchy with arousal. He felt parched, thirsty with the need to keep touching Spock. He hoped Spock wouldn’t notice.

Indeed, Spock seemed too caught up in his own thoughts to pay McCoy much mind. “There must be a slight telepathic response.”

That made McCoy nervous, but he tried to hide it. “You mean you can sense what I’m thinking?”

Spock shook his head. “No, merely that the presence of your mind also stimulates my psi points in addition to nerve clusters stimulated by your touch. This is a testable theory,” he said, holding up his right hand. “The psi points are most densely concentrated in the hand.”

McCoy watched Spock’s long fingers flutter. He thought about arguing that they didn’t need to keep doing this. That he knew now where not to touch Spock. But he quickly discarded the thought. To truly know he would have to touch Spock _everywhere_. After all this was about science...wasn’t it?

He was reaching forward before he’d quite decided to do so, sliding his fingers around Spock’s wrist to hold him still. His other hand pinched at Spock’s palm, rubbing slow, rough circles with his thumb. Spock’s lips parted almost in confusion, his fingers curling inward. McCoy slid his hand higher and took Spock’s index finger between his thumb and forefinger. He slid up, and down, stroking slow and steady, so lightly that he occasionally wasn’t touching Spock at all.

“...Spock?”

“It is…” Spock trailed off and his eyelashes fluttered shut. His mouth was still open and he was panting as McCoy stroked his fingers.

“I need data, Mr. Spock.”

Spock seemed to shake himself. When he spoke his voice was high and thready. “Your touch here is...unique.”

McCoy was starting to get turned on by this whole thing. He shifted around and told himself to stop being such a damned idiot, to stop letting himself imagine that the love-light in Spock’s eyes was anything but a desire for data. Spock’s hand in his gave a spasm, hardly detectable, except that McCoy was holding him so tightly. _Professional_ , he demanded of himself, half panicked. _Stay professional!_

“Unique...how?”

“I feel...electrical impulses. Your skin is cool. I find it fascinating that I cannot anticipate how you will touch me, or where. Quite different from when I touched myself.”

McCoy closed his eyes and swallowed thickly.

“It was still arousing,” Spock went on as if he were talking about the weather. “To touch myself. But when you touch me, Doctor, I sense…” He stopped abruptly and twisted his hand, clasping McCoy harshly.

McCoy’s eyes flew open. “What? What is it?”

Spock’s stare bored into him, dark and dangerous brown, stormy. He held McCoy’s hand like he was afraid McCoy would try to pull away, but also like it was a weapon. A sharp-thorned rose, perhaps, which Spock did not wish to give up but also feared handling. “...It is no matter,” he said after a long moment of this staring, relaxing his shoulders slowly. “Doctor, you wished to know more about Vulcan reproduction?”

McCoy was breathing funny. Spock’s grip on him stirred something in him that he didn’t know existed. He had to put a stop to this. “Spock, I gotta tell you something.”

Spock arched his brow, curious.

“I-I, this isn’t...I’m not sure that I can keep being professional like this.” He flushed hot, trying to figure out how to tell Spock that he was about a second away from jumping him without throwing all respectability out the airlock. “Maybe we should regroup?”

“I have no wish to do so,” Spock told him seriously. “And, I think, neither do you.”

God damn telepathy. He should have known Spock was sensing more than he let on. He pulled his hand away and wiped it off on the front of his shirt. “I’m trying to reason with you—you illogical...Vulcan!”

Spock licked his lip again and this time McCoy caught the act, utterly unable to tear his gaze away from that pink tongue dancing over his plush lower lip. Were they as sensitive as Spock’s hands? Would they quiver if he bit them? “Illogical? Doctor, I am proceeding quite logically. My body has not yet provided you with the data you need to ensure its upkeep.”

McCoy shivered. “You want me to keep touching you?”

“Does it offend you?”

He scoffed. “You’re asking me if I find you offensive? I think you know the answer to that one. I can handle any offense you throw at me.”

Spock’s eyebrow arched again, a challenge this time. “Perhaps there is another who could assist me in acquiring this data.”

 _Abso-fucking-lutely not_ , McCoy thought instantly. “Where else did you try to get a response?”

Spock fanned his long fingers over his soft stomach, never breaking his gaze on McCoy even as McCoy watched his hand intently. “I tried everywhere I was able to reach, Doctor.”

He wanted to order Spock to stop calling him Doctor. Instead, he nodded. “Never let it be said you aren’t diligent, Mr. Spock.” He watched Spock’s fingers trickle over his soft-looking stomach, gulping. He was going to lose it. This was all wrong. But when he looked at Spock all he saw was desire in those brown eyes, hot as melted chocolate. He gulped again. “Alright, then, boots off and up on the bed.”

Spock didn’t even hesitate. He bent and unzipped first one boot, then the other, slipping them from his feet and setting them side-by-side by the table. Then he pulled off his socks and McCoy stared at his bare feet. Had he ever even seen them before? Somehow, that was the most shocking intimacy of all, or at least it was until Spock unfastened the front of his uniform slacks and pulled them down.

McCoy hadn’t told him to do that, but his brain short-circuited before he could think to complain. Spock stepped out of the slacks and then out of his underwear and there he stood, bare to the world—or maybe just to McCoy, who couldn’t look away from him.

Spock was lanky and space-pale, long legs enticing, toes pointed slightly in. McCoy let his gaze meander up the length of Spock’s body, admiring the subtle curve of his hips, the space between his legs glistening wet, his still-pebbled nipples looking positively biteable, his flushed-green chest and neck. Spock was blushing as McCoy looked at him, his body betraying his vulnerability even though his face remained impassive.

As he watched, Spock’s hand came to his hip. For a moment it looked like Spock was going to cover himself but he hesitated, fingers twitching. “Doctor?”

“Get on the bed,” he ordered, voice raw.

Everyone knew Spock was beautiful, and McCoy had known it too, each time he watched Spock on the bridge, or gliding down the halls, head held high, body taut and coiled. But he hadn’t known it like _this_. He’d entertained a few thoughts in his time of getting Spock undressed, touching him until he squirmed, fucking him languid and slow. But he’d never thought it would really _happen_. He couldn’t believe his luck as Spock pushed himself up on the biobed and lay down on his back, limbs falling into place apparently-unconsciously.

McCoy stood at his side, gazing down as Spock looked up at him with wide eyes. Spock was still nervous; he could tell. He knew it by the way Spock’s mouth was slightly parted, eyebrows delicately pinched together. McCoy rested his hand on Spock’s bare thigh and asked, “Are you still aroused?”

Spock hesitated, nodded. He looked down at McCoy’s hand on his leg. “Yes, Doctor.”

He wanted to tell Spock not to call him that, but really who was he to complain? If Spock wanted to keep that imagined-professional distance between them, he would let him. Anyway, he kind of liked the way his title sounded in Spock’s rough voice.

He began to touch Spock’s thighs, brushing his hands down in long, slow passes. “Does it feel the same?”

Spock shivered. Nodded again.

“You’re a walking bundle of nerves, Spock,” he said affectionately, carefully pushing Spock’s legs apart so that he could touch the soft skin of his inner thigh. “I hope you’re keeping notes of all the places that arouse you.”

Spock’s gaze flickered to him and then back down. “Of course,” he said, flashing back for just a moment to the coldly-logical Spock. “Thus far there is no issue, as each spot you touch is arousing.”

McCoy hummed in delight. He had to stand a little wider to give his eager cock some breathing room. It wasn’t the time for that (yet). This was about Spock. “You’re hands were especially sensitive.”

The flush on Spock’s chest rose higher, dusting his high cheek bones. “Yes,” he agreed.

“I think we should investigate the degrees of difference.” He drew one finger up the crease between Spock’s flushed sheathe and his leg, drawing a shiver from Spock. “I have an inkling that this will be a particularly good spot.”

Spock’s mouth hung open. His hands had fallen to the side of the biobed and he gripped the black cushion tightly. “The sensation is...more intense when you—oh!”

Spock’s hips lifted up towards his hand as he trailed his middle finger along the line of Spock’s slit. He was damp there, slick with arousal, and McCoy carefully pushed his way in, sliding so easily into that wet space, and Spock gasped again. McCoy slipped two fingers into Spock’s slit and gently parted them, admiring the pale green of Spock’s inner sheath. Spock’s chest rose and fell with his desperate breathing as McCoy played with his velvety-soft and sensitive skin. Spock's body twitched beneath his hands.

McCoy got a wicked idea and took back his hand, smirking as Spock let out a sound of tormented disappointment. “I’d say that’s hypothesis confirmed,” he said lightly. “No need to go further there.”

Spock looked at him like he’d grown a second head. “Surely, Doctor, a scientific mind like yours desires a more thorough exploration?”

He hummed, rubbing his wet fingers together. “There is something I’m a bit curious about.”

“Yes?” Spock asked, squirming.

“My hands seem to do something for ya, but I’m wondering if touching you with another part of my body would change the sensation.”

Spock’s eyes were black, blown wide. “What will you touch me with, Doctor?”

Instead of telling him, McCoy took Spock’s hips in his hands and drew his bottom down to the edge of the biobed. Spock had to put his feet up on the very edge, knees bent up, and McCoy considered taking out the stirrups but he sort of liked how awkward Spock looked. McCoy spun his chair around and placed it at the end of the bed. He looked down at Spock and let his hand rest against Spock’s ankle, rubbing with his thumb. Even that touch had Spock shivering again and McCoy marveled at how Spock seemed made for sex.

“Spock can you promise me something?”

Spock looked up at him through half-lidded eyes, lips glistening as he panted. “I will.”

“If you want me to stop, just say the word. I’ll stop and we can forget all about this.”

Spock blinked, brow drawing together. “I do not wish to forget—” His mouth formed a shape, tongue flicking over the back of his teeth, a letter _L_ that he quickly swallowed. “Doctor.”

That did it. There was nothing more he could do and so McCoy dropped into the chair and let his breath ghost over Spock’s slick wet sheathe. Spock’s body hitched towards him and he held Spock’s ankles down to keep him from sliding off, flicking out his tongue for just a taste.

“Ah!” Spock twisted as he licked up the line of his slit fast, hungry, and then Spock shuddered as he worked his way back down slowly, tasting every beautiful piece of Spock’s skin.

This morning, if McCoy had been asked what he would be doing today, he would never in a million years have answered, “Eating out the first officer,” and yet here he was with his tongue buried in Spock’s slit, lapping at the sweet trickle of wetness. Spock tasted devine, sweet and rich, and he was so velvety smooth inside that it made McCoy shudder with need. He wrapped his tongue around the shape of Spock’s internal cock and tickled it, licking at it as Spock’s thighs quaked beside his ears. He encouraged it to peek out, bit by bit, licking each piece of sensitive flesh that was exposed. Spock’s breathing grew erratic and McCoy looked up at him, over the slope of Spock’s stomach and heaving chest to where Spock’s head was thrown back, mouth open and his eyes screwed shut in ecstasy.

Spock wasn’t very loud but _damn_ he was unexpectedly expressive.

McCoy had the frantic thought that Spock had been made for this. Made for his touch, his mouth. That Spock’s entire body was devoted to being pleasured. Hell, he could probably get Spock to come just by touching his knee and so he did that, cupping the back of Spock’s knees so that he could push Spock’s bent legs up to his chest and open him further.

Spock’s erection slid against his lips and McCoy licked it again, and then down to where Spock’s slick had ran in rivulets over his hole and McCoy knew that he shouldn’t, that he _really shouldn’t_ , but he still poked out his tongue and circled that quivering ring of muscle, and pushed in.

“Doctor!” Spock’s hips hitched up as McCoy breached him, cock finally slipping out to fall heavy and full and wet on his stomach. His fingers still gripped the edge of the biobed and McCoy heard the metal creaking. “Your...mouth…”

McCoy hummed his agreement and buried his face deeper, thrusting his tongue inside Spock because he _could_ because Spock _wanted it_. Was screaming his desire and openness with every inch of his body, with the heated green of his skin, with his weeping cock and the scent of him flooding McCoy’s senses.

“It is...different,” Spock managed to say. “ _Good_. Doctor, I must confess something.”

McCoy let his tongue slip out of Spock’s body, leaving one last lick over his hole, and then looked up. His lips were wet and so he licked them and watched Spock’s mouth hang open, confused with desire. “Yeah?”

Spock closed his mouth with a click. “I read in the ship’s medical library that the prostate is a source of pleasure for male humans.”

McCoy shuddered. “It is.”

“I...attempted, during my self-exploration, to discover if I would react the same, but I found I could not reach the spot.”

God damn. McCoy closed his eyes at the thought of Spock lying in bed, blankets tangled at his feet, arm reaching back so he could slide his fingers—his sensitive fingers—inside of himself. “Is that your confession?” he asked, opening his eyes again and looking at Spock bare and beautiful before him.

Spock shook his head. “I confess I would like you inside of me.”

He groaned and rested his head on Spock’s leg. “Spock that’s—probably a bit too much to try right away. I don’t want to hurt you.” Also he was certain that he would come eons before actually getting inside of Spock, and he didn’t want to make any promises he couldn’t keep.

Spock looked miffed. “I know what my body is capable of.”

McCoy chuckled and fleetingly wondered when, exactly, Spock had turned this into a seduction. Perhaps right from the start. “How about we see how it feels for you to have a finger inside, and we’ll go from there?”

Spock hummed. “Acceptable,” he said, and then startled as McCoy licked his wet cock again. “That is not—”

“Shh,” McCoy hushed him. “Here, stop destroying my biobed. Hold your knees up to your chest instead.” He watched as Spock painfully released his grip on the bed, leaving eight finger-shaped dents, and took hold of the back of his knees to keep himself open for McCoy. Any trace of shame had left Spock’s body and now McCoy could only read a fervent need in him.

McCoy bent his head again to Spock’s entrance and licked him, delighting at the way Spock shivered beneath his tongue.

“Your finger, Le—you promised a finger, Doctor.”

“I’m getting there, I’m getting there.” He lapped at him again and pointed his tongue, slipping inside easily. Spock opened for him and he took his hand and ran his fingers through the slick still pouring from Spock’s now-neglected erection, and then pressed the tip of his middle finger alongside his tongue.

Spock was so wet with his own arousal, slick with it, loose and relaxed and ready that McCoy slid inside of him with almost no resistance. Spock shuddered at the intrusion, utterly silent save for the panting of his breath. McCoy quirked his finger and curled his tongue, searching, and then the tip of his finger brushed against that little nub.

Spock’s back arched and this time he couldn’t swallow his gasp fast enough. McCoy chuckled and let his tongue slip out, leaving only his finger to press against that gland, rubbing featherlight just to see how it made Spock shiver and keen. He kissed the side of Spock’s erection and with his free hand he reached up between Spock’s bent legs to touch Spock’s chest. He could have touched him anywhere, really, and gotten a reaction, and he delighted in that fact. In the fact that Spock’s entire body was a contradiction to his logical mind. A mind of rationality; a body of sex and passion. He pinched Spock’s nipple in his fingers and sucked his cock into his mouth.

“Doctor,” Spock said, voice high and breathy, but surprisingly steady even as his hips lifted to take McCoy’s mouth. “Your hands...I’ve watched them.”

He groaned around the cock in his mouth, swallowing the slick that poured off of Spock in waves. He loved the shape of it, how heavy and hot it felt inside of him, filling his mouth and stretching his lips. He sucked a little harder just to feel Spock quivering again, driving his finger deeper inside of Spock. The pressure of his own erection against his slacks was too much to bear and he knew with perfect clarity that he was going to come in his own pants without Spock even touching him once, and he didn’t care.

“And now... to feel... _nash-veh...aitlu esta...sanu t’ak'shem, ashayam._ ”

Spock’s words grew mumbled, more Vulcan that McCoyd didn’t understand but loved to hear, and Spock’s hips twitched up, stilted, and McCoy swallowed him again, fingered him as Spock keened, begged in another language and then he felt Spock tightening around his finger and Spock was gasping, words tangled, “ _Ri-gishu!...kup-sarlah nash-veh—ah!—ashayam, sanu,_ please, please it is— _ak’shem...t’ak’shem_ , Leonard, please!”

He was coming too, blitzed out of his mind as Spock pulsated in his mouth. The taste of him changed, salty mixed with sweet and McCoy shuddered and his vision greyed and his whole body was on fire as he emptied out in his pants like he was a teenager again having sex for the first time.

Spock was shaking, panting, body visibly tense with the force of his orgasm. Spock’s moans gradually turned to whimpers of distress and McCoy let him fall from his mouth. Gradually, Spock’s erection began to recede. He waited for Spock to stop twitching so violently and then slowly slid his finger out. He kissed Spock’s inner thigh just for something to do, and because he was afraid to stand up.

Now that it was over McCoy thought, _holy shit_ , and, _what have I done?_

After a moment to catch his breath Spock released his tight grip on his knees. His legs lowered and Spock slipped off the edge of the biobed to stand before McCoy. McCoy looked up at him, eyes wide, and Spock looked down at him, equally surprised.

“Doctor,” he said, and then stopped.

McCoy cleared his throat. “So, uh. Data.”

“Yes.” Spock’s hand jerked but then he didn’t seem to know what to do with it, so it fell back to his side. “We have certainly gathered a great deal of data.”

“Uh,” McCoy said again, and felt quite proud at how lucid he was despite still crashing down from the high of his own orgasm.

“Do you wish for me to—” Spock made that aborted hand gesture again, his gaze falling to McCoy’s groin.

McCoy flushed. “No, er… That sort of took care of itself.”

Spock looked contemplative and god damnit, didn’t he know he was still naked? “Is that usual for humans?”

His blush deepened. “Depends on how good the sex is.”

Sex. He’d said the word out loud and somehow that seemed to make it real. That was what they had just done. _Sex_. They had fucked. He’d fucked the first officer. Well, mostly he’d blown the first officer, but still. Sex. They’d had sex. Sex in Sickbay, on duty, because once he’d gotten his hands on Spock he’d been utterly unable to stop himself. And Spock didn’t even seem ruffled.

“Then it was good?” Spock asked, voice unexpectedly heated.

McCoy sucked in a breath and tried to read the look on Spock’s face. “Yeah,” he managed finally. “It was...really good.”

“We would be remiss,” Spock said, suddenly walking away from McCoy to grab his clothes and begin getting dressed again. McCoy watched him go, flabbergasted. “If we did not attempt a repeated experiment.”

“Um.”

“The scientific method relies on the reproducibility of results.” Spock shot him a glare, as if this were all very obvious. “Do you not agree?”

“I guess.”

Spock’s eyebrow hitched up. “Fascinating.”

“What? What is?”

“I have discovered the necessary stimuli in order to prevent you from disagreeing with my every move.”

“What?” He puffed up, annoyed. “Where do you—”

Spock bent and pressed his lips against McCoy’s temple and McCoy melted in relief at the contact. Spock whispered to him, soft and sweet, “I wish for you to touch me again, Doctor.”

They would have to have a chat about names, but right then McCoy didn’t want to push his luck. He nodded, trying to play it cool and not seem too eager even though he was about to burst. “I’d like that, too, Mr. Spock,” he said, low and throaty.

Spock shivered just from his voice, and McCoy beamed at him. “I will be in my quarters tonight at 1800 hours. Will you join me for dinner?”

“Yes,” McCoy answered immediately, and then he forced himself to relax. “Yeah, I’ll...be there.”

Spock seemed amused by him. He was fully dressed now, neat and proper and McCoy envied him and tried not think about how he was going to have to sneak back to his quarters in a few minutes for a change of pants. Spock kissed his temple again. “Until then, Doctor. Good day.”

Spock was nearly to the door when McCoy thought of something. “Spock?”

Spock turned to look at him, one eyebrow arched. “Yes, Doctor?”

“Can you... _not_ have your quarters at 45C tonight?”

Spock pursed his lips as if considering. “If I do not I will be cold.”

McCoy smirked and watched Spock flush green at the sight. “Don’t you worry, darlin’,” he purred. “I’d be much obliged to keep you warm tonight.”

**Author's Note:**

> The Vulcan phrases:
> 
> The first one is: "(And now to feel)...I...desire your touch...please pleasure me, beloved."
> 
> Second: "Coming! ...I'm going to come (ah!) beloved, please, (please, please it is) pleasure...my pleasure, (Leonard, please!)"


End file.
